Morbid obesity and mortality in patients with venous thromboembolism. Findings from real life clinical practice

Abstract Background The influence of morbid obesity on mortality in patients receiving anticoagulant therapy for venous thromboembolism (VTE) has not been consistently evaluated. Methods We used the data from RIETE registry to compare the mortality risk during anticoagulation in VTE patients with morbid obesity (body mass index [BMI] ≥40) versus those with normal weight (BMI: 18.5-24.9). Patients with or without active cancer were analyzed separately. Results By September 2018, there were 4,443 VTE patients with morbid obesity and 12,047 with normal weight in RIETE. Of these, 245 (5.5%) and 1,397 (11.6%) respectively had cancer. Median duration of anticoagulant therapy was longer in the morbidly obese, with- (185 vs. 114 days) or without cancer (203 vs. 177 days). Among cancer patients, 44 (18.0%) morbidly obese and 1,377 (32.8%) patients with normal weight died during anticoagulation. Among those without cancer, 44 (3.1%) and 601 (5.6%) respectively died. On bivariate analysis, morbid obesity was associated with a lower mortality rate, both in patients with cancer (hazard ratio [HR]: 0.34; 95%CI: 0.25-0.45) and in those without cancer (HR: 0.43; 95%CI: 0.32-0.58). Multivariable analysis confirmed a lower hazard of death in morbidly obese patients with- (HR: 0.68; 95%CI: 0.50-0.94) or without cancer (HR: 0.67; 95%CI: 0.49-0.96). The risk for VTE recurrences or major bleeding did not differ in patients with or without morbid obesity. Conclusions In patients with VTE, the risk for death during anticoagulation was about one third lower in morbidly obese patients than in those with normal weight, independently of the presence of cancer.